Construction and Commissioning of Infrared SASE-FEL at cERL

Abstract

To demonstrate the operation of a mid-infrared SASE FEL system in an energy recovery linac (ERL) layout, we constructed an SASE FEL setup in cERL, a test facility of the superconducting linac at KEK. Despite the adverse circumstance due to the given boundary condition of the facility and the limited budget and time schedule of the project, we successfully established the beam condition at the undulators, and observed FEL emission at a wavelength of 20 µm. We present the background stories that we have experienced in the project.